Process for making printing blocks and stamps.



UNITE sra'rns ALFRED J. J'ARMAN, OF NEW YORK, Y., ASS IGNOR OF ONE-HALF T0 JOHN F. WICKENS, OF NEW YORK, N. Y.

PROCESS FOR MAKING PRINTING BLOCKS AND STAMPS.

No Drawing.

To all whom fit may concern:

Be it known that I, ALFRED J. JARMAN, a subject of the King ofEngland, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, haye invented a new and Improved Process for Making Printing Blocks and Stainps, of which the following is a full, clear, and 'exact description. I

The invention relates to the process of making printing blocks and stamps from photographic negatives by the use of a specially prepared printing papen'a' mold, and a die from which a bas-relie fcan be obtained. and an object of the invention is to provide an expeditious and economical process whereby innumerable representatimis of a photograph canbe quickly reproduced.

To accomplish the desired result a suitable negative is obtained by the use of a screen,

as employed in half-tone work with approximately fifty lines to the inch. Paper of a desired quality is then coated with a prepa ration consisting of gelatin and sugar with a small quantity of soap mixed therein. 'lhis preparation may be impregnated with coloring matter if desired, and preferably consisting of (hina ink or sugar that has been charred by means of sulfuri acid or the. like. After the. mentioned preparation has been suitably atlixed to the paper and dried the paper is made sensitive to light by immersing the same in a cold solution of potassium bichromate of a strength propor tionate to the negative to be employed in the process. The paper is now thoroughly dried in a room free from all actinic light and is then exposed under the mentioned negative in the usual manner until an image of sufficient density is formed; after which the paper is plunged into cold water and thoroughly saturated. After being saturated, the paper is pressed onto a plate of metal or glass. preferably opal glass. which has been previously coated with gelatin, and after becoming sutliciently dry, treated with a five or' six per cent. solution of formaldehyde so as to n'iake the gelatin coating partially insoluble, and the said paper s suit ably secured to the plate. by the use of a squeegee. The prepared plate having the paper attached thereto is now placed in a tray of warm water to which a trace of soap has been added. and in a few moments the gelatin dissolves and the paper is carefully Specification of Letters Iatent.

Patented Aug. 15, 1911.

Application filed October '3, 1910. Serial No. 584,956.

removed from the plate leaving the gelatin upon the plate. The use of soap in the water materially aids in the rapid and ef-' ficient dissolution of thegelatin as the alkali which is contained in the soap has a direct action upon the unaffected parts of the gelatin while not atfectlng the gelatin which has been acted upon by the light. The gelatin plate with the image thereon is now washed in a soapy 'ater to remove all superfluous matter and then dried without being treated with'a hardening solution. After 'beingallowed to dry the image on the plate will appear -in considerable relief as will be readily understood. This plate is now placed in cold water and permitted to soak, after which it is transferred to a tray of formalin of a five or six per cent/solution and then surface dried and coated with a mixture of castor oil, linseed oil and spirits P of turpentine in approximately equal parts. Any excess of oil is removed from the newly coated surface of the platei it is'carefully wiped clean and is then placed into a metal frame preparatory to obtaining a mold of the image on the-plate. A mixture of plum- V bago. gypsum and water or Portland cement and water with a quantity f talcum powder added to the first mixture, is then provided and poured into the frame to cover the image on the plate and constituting a mold. After the mold has become sntliciently dry the plate removed therefrom and representation of the in'iage on the plate will be disclosed in the mold. By en'iploying rubber or celluloid and a vulcanizing press for heating the mold. the rubber or celluloid can be easily pressed into the image disclosed in the mold and a has-relief of the image will be formed on the rubber or celluloid thus providing the printing stamp or block required.v

When the mold is madeof the mentioned plumbago and gypsum mixture the desired stamps are made by using soft. or Vtlltitll'iiZ iug rubber and when it is desired to provide hard rubber or celluloid printing stamps metal mold is constructed. i The presence of soap in the gelatin -iiacilitates very much the separation of the mold from the gelatin plate. this mold being afterward used in a vulranizing press for making the rubber stamp. By reason of fact that. the hichromatcd plate was printed thrmigh a. negative obtained through screen, it will be seen that the bichromated plate after development presents a surface which is made up of an innumerable quantity of minute projections resulting from the ruling on the screen; it has been a difficult matter to make a mold which may be easily separated from the gelatin plate and still present all of the aforesaid projections, since in the step of separating the mold from the plate more or less of these projec- -tic ns are destroyed because of the mold w ture, and the said image is placed in a strong solution of protosulfate of iron or hydro- ,quinon, after which the same is washed in clean water and then placed in'a solution of nitrate of silver or chlorid of gold, which in turn will cause a deposit of metal both upon and in the body of the gelatin image, thus thoroughly impregnating the same with the metal. This operation is repeated until the image is absolutely covered by a depositof metal and the image is then surface dried and placed into an electrotyping bath of sulfateof copper, which will cause a deposit of copper to form on the plate after which a metal back plate is soldered to the copper deposit to increase the metal thickness.

As mentioned heretofore by employing hardrubberor celluloid an impression of the image on the plate can be easily conveyed to the rubber or celluloid, it being understood that these substances are preferably adapted for the particular use mentioned.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

The herein-described method for producing printing blocks and stamps from photographic negatives which consists in making a printfrom a screen negative on suitable material covered with bichromatcd gelatin having soap incorporated therein, transferring the said gelatin. coating-with the soap therein from the said material onto a suitable plate and working the same to disclose the image thereon in relief, making an imprint of the said image in a plastic mass consisting of a mixture of plumbago and cement, whereby to form a mold, and. then placing the mold in contact with suitable material in a press whereby a stamp or printing block is obtained.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALFRED J. J ARMAN.

WVitnesscs SAMUEL M. Rmss, PHILIP .D. ROLLHAUS. 

